/* flip.c - image flip
 *
 * Raster graphics library
 *
 * Copyright (c) 2014-2021 Window Maker Team
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
 *  MA 02110-1301, USA.
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <X11/Xlib.h>

#include "wraster.h"
#include "rotate.h"

static RImage *r_flip_vertically(RImage *source);
static RImage *r_flip_horizontally(RImage *source);

/* Flip an image in the direction(s) specified */
RImage *RFlipImage(RImage *source, int mode)
{
  /* Security */
  if (source == NULL)
    return NULL;

  switch (mode & (RVerticalFlip | RHorizontalFlip)) {
    case RHorizontalFlip:
      return r_flip_horizontally(source);

    case RVerticalFlip:
      return r_flip_vertically(source);

    case RHorizontalFlip | RVerticalFlip:
      return wraster_rotate_image_180(source);

    default:
      return RRetainImage(source);
  }
}

RImage *r_flip_vertically(RImage *source)
{
  RImage *target;
  int nwidth, nheight;
  int x, y;

  nwidth = source->width;
  nheight = source->height;

  target = RCreateImage(nwidth, nheight, (source->format != RRGBFormat));
  if (!target)
    return NULL;

  if (source->format == RRGBFormat) {
    unsigned char *optr, *nptr;

    optr = source->data;
    nptr = target->data + 3 * (nwidth * nheight - nwidth);

    for (y = 0; y < nheight; y++) {
      for (x = 0; x < nwidth; x++) {
        nptr[0] = optr[0];
        nptr[1] = optr[1];
        nptr[2] = optr[2];

        optr += 3;
        nptr += 3;
      }
      nptr -= (nwidth * 3) * 2;
    }
  } else {
    unsigned char *optr, *nptr;

    optr = source->data;
    nptr = target->data + 4 * (nwidth * nheight - nwidth);

    for (y = 0; y < nheight; y++) {
      for (x = 0; x < nwidth; x++) {
        nptr[0] = optr[0];
        nptr[1] = optr[1];
        nptr[2] = optr[2];
        nptr[3] = optr[3];

        optr += 4;
        nptr += 4;
      }
      nptr -= (nwidth * 4) * 2;
    }
  }
  return target;
}

RImage *r_flip_horizontally(RImage *source)
{
  RImage *target;
  int nwidth, nheight;
  int x, y;

  nwidth = source->width;
  nheight = source->height;

  target = RCreateImage(nwidth, nheight, (source->format != RRGBFormat));
  if (!target)
    return NULL;

  if (source->format == RRGBFormat) {
    unsigned char *optr, *nptr;

    optr = source->data;
    nptr = target->data + 3 * (nwidth - 1);

    for (y = nheight; y; y--) {
      for (x = 0; x < nwidth; x++) {
        nptr[0] = optr[0];
        nptr[1] = optr[1];
        nptr[2] = optr[2];

        optr += 3;
        nptr -= 3;
      }
      nptr += (nwidth * 3) * 2;
    }
  } else {
    unsigned char *optr, *nptr;

    optr = source->data;
    nptr = target->data + 4 * (nwidth - 1);

    for (y = nheight; y; y--) {
      for (x = 0; x < nwidth; x++) {
        nptr[0] = optr[0];
        nptr[1] = optr[1];
        nptr[2] = optr[2];
        nptr[3] = optr[3];

        optr += 4;
        nptr -= 4;
      }
      nptr += (nwidth * 4) * 2;
    }
  }
  return target;
}
